SMD LED 19-219 Brilliant Yellow Datasheet - Size 1.6x0.8x0.65mm - Forward Voltage 1.7-2.2V - Luminous Intensity 18-45mcd - English Technical Document

1. Product Overview

The 19-219 is a surface-mount device (SMD) LED emitting a brilliant yellow color. It is designed using AlGaInP chip technology encapsulated in a water-clear resin. Its primary advantages include a compact form factor, compatibility with automated assembly processes, and compliance with modern environmental and safety standards such as RoHS, REACH, and halogen-free requirements.

1.1 Core Advantages and Target Market

The significantly smaller size compared to lead-frame type LEDs enables higher packing density on printed circuit boards (PCBs), leading to reduced overall equipment size and weight. This makes it particularly suitable for miniature and space-constrained applications. The device is packaged on 8mm tape wound on a 7-inch diameter reel, facilitating high-speed automated pick-and-place assembly. Its primary target markets include consumer electronics, automotive interiors, telecommunications equipment, and general indicator applications where reliable, compact illumination is required.

2. Technical Parameter Deep Dive

This section provides a detailed, objective analysis of the key electrical, optical, and thermal parameters specified for the 19-219 LED.

2.1 Absolute Maximum Ratings

The absolute maximum ratings define the limits beyond which permanent damage to the device may occur. These are not operating conditions.

• Reverse Voltage (V_R): 5V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Continuous Forward Current (I_F): 25 mA. The maximum DC current that can be applied continuously.
• Peak Forward Current (I_FP): 60 mA. This is permissible only under pulsed conditions (duty cycle 1/10 at 1 kHz) to handle transient surges.
• Power Dissipation (P_d): 60 mW. The maximum power the package can dissipate, calculated as V_F * I_F.
• Electrostatic Discharge (ESD) Human Body Model (HBM): 2000V. Indicates a moderate level of ESD robustness; standard ESD handling precautions are still necessary.
• Operating Temperature (T_opr): -40°C to +85°C. The ambient temperature range over which the device is specified to operate.
• Storage Temperature (T_stg): -40°C to +90°C.
• Soldering Temperature: The device can withstand reflow soldering with a peak temperature of 260°C for up to 10 seconds, or hand soldering at 350°C for up to 3 seconds per terminal.

2.2 Electro-Optical Characteristics

These parameters are measured at a standard test condition of I_F = 5 mA and T_a = 25°C, unless otherwise noted. They represent typical performance.

• Luminous Intensity (I_v): 18 to 45 millicandelas (mcd). This wide range is managed through a binning system (see Section 3). The tolerance is ±11%.
• Viewing Angle (2θ_1/2): 130 degrees (typical). This is the full angle at which the luminous intensity drops to half of its peak value, indicating a wide viewing pattern.
• Peak Wavelength (λ_p): 591 nm (typical). The wavelength at which the spectral power distribution is maximum.
• Dominant Wavelength (λ_d): 585.5 to 594.5 nm. This defines the perceived color (yellow) and is also subject to binning. Tolerance is ±1 nm.
• Spectral Bandwidth (Δλ): 15 nm (typical). The width of the emitted spectrum at half the maximum intensity.
• Forward Voltage (V_F): 1.7 to 2.2 V at 5 mA. This range is managed by voltage binning. The tolerance is ±0.05V.
• Reverse Current (I_R): 10 μA (max) at V_R = 5V.

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into bins based on key parameters.

3.1 Luminous Intensity Binning

Bins are defined by minimum and maximum luminous intensity values at I_F=5mA.

• Bin M1: 18.0 - 22.5 mcd
• Bin M2: 22.5 - 28.5 mcd
• Bin N1: 28.2 - 36.0 mcd
• Bin N2: 36.0 - 45.0 mcd

3.2 Dominant Wavelength Binning

LEDs are grouped by their precise dominant wavelength to maintain color uniformity.

• Group A, Bin D3: 585.5 nm
• Group A, Bin D4: 588.5 nm
• Group A, Bin D5: 591.5 nm

3.3 Forward Voltage Binning

Sorted into 0.1V steps to aid in circuit design, particularly for current-limiting resistor calculation and power management.

• Bin 19: 1.7 - 1.8 V
• Bin 20: 1.8 - 1.9 V
• Bin 21: 1.9 - 2.0 V
• Bin 22: 2.0 - 2.1 V
• Bin 23: 2.1 - 2.2 V

4. Performance Curve Analysis

The datasheet provides several characteristic curves that are crucial for understanding device behavior under different operating conditions.

4.1 Relative Luminous Intensity vs. Forward Current

This curve shows that light output increases with current but not linearly. At very low currents, the increase is steep, but it tends to saturate at higher currents due to efficiency droop and thermal effects. This highlights the importance of driving the LED at its specified current for optimal brightness and longevity.

4.2 Forward Current vs. Forward Voltage (I-V Curve)

The I-V curve is exponential, typical of a diode. A small change in forward voltage results in a large change in forward current. This underscores the critical need for a constant-current driver or a well-calculated series resistor to prevent thermal runaway and device failure.

4.3 Relative Luminous Intensity vs. Ambient Temperature

LED light output decreases as the junction temperature rises. This curve quantifies the derating, showing that luminous intensity can drop significantly as the ambient temperature approaches the maximum operating limit. Effective thermal management on the PCB is essential to maintain consistent brightness.

4.4 Forward Current Derating Curve

This graph defines the maximum allowable continuous forward current as a function of ambient temperature. To ensure reliability, the forward current must be reduced when operating at high ambient temperatures to keep the junction temperature within safe limits.

4.5 Spectrum Distribution and Radiation Pattern

The spectrum plot confirms the monochromatic yellow emission centered around 591 nm. The radiation diagram illustrates the Lambertian-like emission pattern with a wide 130-degree viewing angle, suitable for applications requiring broad area illumination.

5. Mechanical and Package Information

5.1 Package Dimensions

The device has a compact footprint. Key dimensions (in mm) include: Length: 1.6 ±0.1, Width: 0.8 ±0.1, Height: 0.65 ±0.1. The cathode is identified by a specific pad geometry or marking on the package bottom.

5.2 Recommended Soldering Pad Layout

A suggested land pattern is provided for PCB design, with dimensions for the anode and cathode pads. The design includes thermal relief and proper spacing to ensure reliable soldering and mechanical stability. Engineers are advised to modify this pattern based on their specific PCB manufacturing process and thermal requirements.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

A lead-free reflow profile is specified: Preheat: 150-200°C for 60-120s; Time above liquidus (217°C): 60-150s; Peak temperature: 260°C max for 10 seconds max. The maximum heating and cooling rates are also defined to minimize thermal stress on the component.

6.2 Critical Precautions

• Current Limiting: An external current-limiting resistor is mandatory. The LED's exponential I-V characteristic means even slight supply voltage variations can cause destructive current spikes.
• Reflow Cycles: Do not subject the LED to more than two reflow soldering cycles.
• Mechanical Stress: Avoid applying stress to the LED body during soldering or board handling. Do not warp the PCB after assembly.
• Hand Soldering: If necessary, use a temperature-controlled iron (<350°C) with a tip smaller than 25W capacity. Limit contact time to 3 seconds per terminal with adequate cooling intervals between leads.

7. Storage and Handling

The device is moisture-sensitive (MSL).

• Before Opening: Store at ≤30°C and ≤90% RH.
• After Opening: The "floor life" under ≤30°C/≤60% RH is 1 year. Unused devices must be resealed in their moisture-proof bag with desiccant.
• Baking: If the storage time is exceeded or the desiccant indicator shows moisture ingress, bake at 60 ±5°C for 24 hours before use to remove absorbed moisture and prevent "popcorning" during reflow.

8. Packaging and Ordering Information

The standard packaging is 3000 pieces per reel on 8mm carrier tape. The reel dimensions are provided for automated feeder setup. The label on the reel includes information such as part number, quantity, luminous intensity bin (CAT), dominant wavelength bin (HUE), forward voltage bin (REF), and lot number.

9. Application Suggestions

9.1 Typical Application Scenarios

• Automotive Interior: Backlighting for dashboard instruments, switches, and control panels.
• Telecommunications: Status indicators and keypad backlighting in phones and fax machines.
• Consumer Electronics: Flat backlighting for small LCDs, switch illumination, and symbolic indicators.
• General Purpose Indication: Power status, mode selection, and alert indicators in various electronic devices.

9.2 Design Considerations

• Drive Circuit: Always use a series resistor or constant-current driver. Calculate the resistor value using R = (V_supply - V_F) / I_F, considering the worst-case V_F from the binning range.
• Thermal Management: Although low-power, ensure adequate PCB copper area or thermal vias if operating at high ambient temperatures or near maximum current to maintain light output and lifespan.
• Optical Design: The wide viewing angle is suitable for direct viewing. For focused light, an external lens may be required.

10. Technical Comparison and Differentiation

The 19-219 LED's primary differentiation lies in its combination of a very small 1608 package size (1.6x0.8mm) with a relatively high luminous intensity for its class (up to 45 mcd). The use of AlGaInP technology provides efficient yellow emission. Its compliance with halogen-free and stringent RoHS/REACH standards makes it suitable for global markets with strict environmental regulations. Compared to larger through-hole LEDs, it enables significant miniaturization and automated assembly cost savings.

11. Frequently Asked Questions (Based on Technical Parameters)

Q: Why is a current-limiting resistor absolutely necessary?
A: The LED's forward voltage has a negative temperature coefficient and a tight manufacturing tolerance. Without a resistor, a small increase in supply voltage or a drop in V_F due to heating can cause current to increase uncontrollably, leading to immediate failure.

Q: Can I drive this LED at 20mA continuously?
A: Yes, the maximum continuous forward current rating is 25 mA. Operating at 20mA is within specification, but you must ensure the ambient temperature is considered using the derating curve. At high ambient temperatures, the maximum allowable current is lower.

Q: What do the bin codes (M1, D4, 21) mean for my design?
A> They ensure consistency within a production run. For example, using LEDs from the same luminous intensity bin (e.g., N2) ensures uniform brightness across an array. Using the same voltage bin simplifies current-limiting resistor calculation. For critical color applications, specifying the dominant wavelength bin (e.g., D4) is essential.

Q: How do I interpret the 1-year floor life?
A> Once the moisture-proof bag is opened, the components can absorb atmospheric moisture. If not used within one year under controlled conditions (30°C/60% RH), they must be rebaked before reflow soldering to prevent internal package damage from rapid vapor expansion.

12. Practical Design and Usage Case

Case: Designing a status indicator panel with 10 uniform yellow LEDs.

1. Specification: Target forward current I_F = 10 mA for a balance of brightness and longevity. Supply voltage V_supply = 5V.
2. Binning Selection: To ensure visual uniformity, specify LEDs from a single luminous intensity bin (e.g., N1: 28.2-36.0 mcd) and a single dominant wavelength bin (e.g., D4: 588.5 nm).
3. Resistor Calculation: Use the maximum forward voltage from the selected voltage bin for a conservative design. If using Bin 22 (V_{F_max} = 2.1V), R = (5V - 2.1V) / 0.01A = 290 Ω. The nearest standard value (300 Ω) would result in I_F ≈ 9.7 mA, which is safe and within the target.
4. PCB Layout: Place the LEDs with the recommended pad layout. Include a small copper pour connected to the cathode pads for slight thermal improvement. Ensure the current-limiting resistors are placed close to the LED anodes.
5. Assembly: Follow the specified reflow profile. After assembly, inspect under low magnification for proper solder fillets and alignment.

13. Operating Principle Introduction

Light emission in this LED is based on the principle of electroluminescence in a semiconductor p-n junction. The chip material is Aluminum Gallium Indium Phosphide (AlGaInP). When a forward voltage is applied, electrons from the n-type region and holes from the p-type region are injected into the active region where they recombine. The energy released during this recombination is emitted as photons (light). The specific composition of the AlGaInP alloy determines the bandgap energy, which directly defines the wavelength (color) of the emitted light—in this case, brilliant yellow (~591 nm). The water-clear epoxy resin encapsulant protects the chip and acts as a lens, shaping the radiation pattern.

14. Technology Trends and Context

The 19-219 LED represents a mature SMD LED technology. Current industry trends in indicator LEDs continue to focus on several areas relevant to this product: further miniaturization (e.g., 1005, 0402 packages), increased luminous efficacy (more light output per unit of electrical input), and enhanced reliability under harsh conditions (higher temperature, humidity). There is also a strong drive towards broader spectral options within a single package size and improved color consistency through tighter binning. The environmental compliance (Halogen-Free, REACH) highlighted in this datasheet is now a standard expectation for components sold in global markets, reflecting the industry's response to regulatory and sustainability demands.